Recent content by JimK

Interesting discussion, all based on people not defining their assumptions when they present a result. Thanks for the reference.

I've given into using the Surface area for both CD and CL. I ran across a post that said the surface area used to calculate CD is SPAN*CHORD, which is the Surface area. After doing the new calculation, it turns out the difference between using the Frontal area and the Surface area is very...

Thanks for the feedback. I completely agree with your logic. It would be really helpful if they would define the area they use to get the two coefficients. One argument I've heard is that they are usually used for small angles of attack. For this case, the drag is predominantly due to...

I agree. The problem seems to be that the references to the coefficients don't cite the definition of the area used to derive them. For now, I'm going to assume: Frontal area for drag. Surface area for lift. Thank you for your help. Jim

Thank you for your quick reply. I appreciate it. I am already taking into account the variable Cd and Cl as a function of angle of attack. I've fitted curves to the published table data. I'm using the Frontal area for my drag calculations. However, I'm using the total Surface area for...

I'm trying to calculate the aerodynamic forces on a flat plate as a function of angle of attack. The drag force is calculated from F = ρ*V^2*A*Cd/2 Where ρ is the air density, V is the wind velocity, A is the area, and Cd is the drag constant. Simple question: For A, should I use...